Captive bolt pistol for animal stunning

ABSTRACT

In a captive bolt pistol, the barrel and the breech block are incorporated in a unit which is rotatable about the barrel axis between a firing position and a spent cartridge extracting position, and the unit is provided with a cam adapted to cock the firing mechanism of the pistol as the unit is tapered from the former to the latter of the said positions.

United States Patent [191 Hancox 51 Apr. 17, 1973 I CAPTIVE BOLT PISTOL FOR ANIMAL FOREIGN PATENTS OR APPLICATIONS STUNNING 907,815 7/1945 France ..'......42/1 M [75] Inventor: Roger John Hancox, Bumtwood,

' England Primary ExaminerBenjamin A. Borchelt Assistant ExaminerC. T. Jordan [73] Assignee: Accles 8: Shelvoke Limited, Aston, Anomey lmirie & Smiley Birmingham, England [22] Filed: Sept. 16, 1971 ABSTRACT Appl. No.: 181,029

U.S. ..42/l M, 17/1 B, 42/395 Int. Cl. ..A22b 3/02, F4lc 1 1/00 Field of Search ..42/l M, 1 R, 39.5;

References Cited UNITED STATES PATENTS Arrowsmith ......-42/l M In a captive bolt pistol, the barrel and the breech block are incorporated in a unit which is rotatable about the barrel axis between a firing position and a spent cartridge extracting position, and the unit is provided with a cam adapted to cock the firing mechanism of the pistol as the unit is tapered from the former to the latter of the said positions.

10 Claims, 8 Drawing Figures PATENTEDAfRI 71975 3 727, 337

SHIIET 1 [1F 3 PATENTED 3,727,337

sum 3 BF 3 This invention relates to captive bolt pistols, such as used in the humane slaughtering of animals, wherein a bolt accommodated within the barrel of the pistol, is adapted to be projected outwardly of the muzzle of the barrel into violent impact with an animals skull, upon firing a cartridge in the breech block of the pistol.

The principal object of the present invention is to enable the firing mechanism of a captive bolt pistol to be cocked quickly and easily.

Further objects of the invention are to minimize, first, the possibility of the pistol being fired inadvertently whilst the firing mechanism is cocked and,

secondly, the number of component parts which are moved when the pistol is fired.

Still another object of the invention is to enable the pistol to be converted for use by a left-handed instead of a right-handed person, or vice versa.

In accordance with the said invention, the barrel and breech block of a captive bolt pistol are incorporated in a unit whichis rotatable about the barrel axis between a firing position and a spent cartridge extracting position, and is provided with a cam adapted to cock the firing mechanism of the pistol as the unit is turned from the former to the latter of the said positions.

In order that the invention may be understood and carried into practice, it will now be described with reference to the accompanying drawings in which:

FIG. 1 is a part-sectional elevation of a pistol constructed in accordance with one typical embodiment of the invention, the breech block being in its firing position and the firing mechanism being cocked,

FIG. 2 is a part-sectional elevation showing the breech block in itsspent cartridge extracting position,

FIGS. 3 8L 4 are, respectively, sections along the lines III-III, FIG. 1, and IV-IV, FIG. 2,

FIG. 5 is a plan of the pistol as shown in FIG. 1,

FIG. 6 is a diagrammatic part-sectional elevation of part of a pistol constructed in accordance with a second embodiment of the invention, the breech block being in its spent cartridge extracting position,

FIG. 7 is a sectional elevation of the breech of the pistol shown in FIG. 6, the breech block being in its firing position-and the firing-mechanism beingcocked; and

FIG. 8 is a sectional elevation similar to that shown in FIG. 7, but showing the firing mechanism tripped.

- The captive bolt pistol shown in FIGS. 1 to 5 includes a unit which comprises a barrel 1 and breech block 2 and-which extends through and is rotatable about the barrel axis in, but is held against axial movement relatively to, an open-ended housing3 integral with and located above the pistol body 4.

The unit is adapted to be rotated manually within the housing 3 by gripping and turning a cap 5 which surrounds andis secured to the muzzle of the barrel and has a central hole (not shown) in its base.

One end of a bolt 6 extends through the hole in the cap base. The bolt 6 is concentric to the barrel 1 and is integral with a piston having a larger diameter portion 7 which is a sliding fit within the barrel bore, and a smaller diameter portion 8 which is a sliding fit within a co-axial firing chamber 9 in the breech block. A group of resilient rebound bushes 10 of smaller diameter than the barrel bore, surrounds the bolt 6 between the piston portion 7 and the base of the cap 5. g

The breech block has a radial cartridge chamber 1] which opens to the periphery of the block externally of the housing 3 and, at its inner end, sweeps through 90 and opens into the firing chamber.

At its end remote form the housing, the breech block is formed with an integral, semi-circular shoe 12 of which the external convex surface seats upon a saddle 13 integral with and extending rearwardly from, the body and housing. The shoe'l2 and the saddle 13 are concentric.

A cam groove 14 is formed in the external surface of and extends from one longitudinal edge to'the other, of the semi-circularshoe. A coiled torsion spring 15 carried around a pivot pin extending across a cavity 16 in the heel of the saddle, has two arms 17, 18 extending substantially radially to the axis of the pivot pin. The cavity 16 opens to the upper surface of the saddle 13 below the shoe l2 and to the lower end of a vertical passage 19 extending through the saddle and opening to the said upper surface below the breech block. A firing pin 20 having aperipheral shoulder 21 between its ends and a transverse recess 22 between the shoulder I and its lower end, is accommodated within, and is slidable lengthwise of the passage, the spring arm 17 projects from the cavity into engagement with the cam groove so that it is adapted to act asacam follower, and the spring arm 18 projects from the cavity intoengagement with the recess 22. a

The firing pin 20 traverses, first, a longitudinal passage 23 in the body 4 and saddle l3, and, secondly,

Y a longitudinal slot 24 in the breech end of one part 25 spring 36 by depressing the thumb piece.

of a two-part sear rod 25, 26 of which the other part 26 projects beyond the muzzle end ofthe longitudinal passage and is formed, on its projecting end, with a finger piece 27. j

The sear rod parts 25, 26 are, respectively, urged muzzlewards by a coiled compression spring 28 and a weaker coiled compression spring 29, the spring-driven travel of the part 26 being limited by a pin 30 extending through the pistol body and tangentially of the longitudinal passage and engaging a segmental recess 31 in the top of the sear rod part, whereas the: spring-driven travel of the slotted part 25 is limited by abutment of its muzzle end with the breech end of the recessed part 26.

A safety catch 32 carried in a 'transverse slot 33 formed in 'the body 4 below the longitudinal passage 23, is provided with a thumb-piece 34 which (see FIGS. 3 and 4) projects beyond the left-hand side of the body. The catch 32 is formed, in its end remote from the thumb-piece, with an outwardly I and downwardly inclined jaw with engages a correspondingone of a pair of pins 35 located parallel to and equidistantly from the longitudinal passage and spaced apart transversely of the body. 1 I

A coiled compression spring 36 projecting from a handle or grip 37 assembled to the underside of the body by a bolt 38, abuts the underside of the safety catch midway between the two pins 35, thereby pivoting the catch upwardly about the jaw-engaged pin into abutment with the other of the said pins and into abutment with a segmental recess 39 in the underside of the sear rod part 26 and locking the said part against longitudinal movement in the pistol body until the safety catch is swung downwardly againstthe action of the 19, upwards, spring-driven travel of the said pin is prevented by the abutment of its shoulder against the underside of the sear rod part 25 rearwardly of slot 24, and the said passage is in axial alignment with the cartridge chamber 11.

To trip the mechanism and, provided a cartridgehas been inserted into the chamber 11, fire the pistol whilst the grip 37 is being held in the right hand of an operator, the operator depresses the thumb-piece with the thumb of the hand so as to disengage the safety catch from the recess 39, and then presses upon the finger piece 27 with the forefinger of the hand, thereby displacing the sear rod and disengaging the breech end of the part 25 from the shoulder 21, whereupon the arm 18 of the stressed torsion spring drives the firing pin rapidly upwards into impact with the cartridge. Upon removing or relieving the pressure applied to the finger piece 27, the spring 29 returns the rod part 26 to its initial position in which it is locked automatically by the safety catch, but spring-driven return movement of the rod part 25 is prevented by abutment of the breech end To re-cock the firing mechanism, the barrel and breech block unit is rotated, clockwise'as viewed in FIGS. 3 and 4, whereupon the cam groove, acting of the slot 24 against the firing pin below the shoulder through the spring arm 17, turns the torsion spring counter-clockwise, as viewed in FIGS. 1 and 2, with the result that the arm I8 drives the firing pin downwardly until the shoulder 21 moves below the rod part 25 and the latter is driven by the spring 28 so that its breech end overhangs the shoulder. The clockwise travel of the unit is limited by abutment (see FIG. 4) ofa stud ,40 fixed in and projecting radially from, the breech block against the right hand longitudinal edge of the saddle 13. As the unit rotates, one end of an extractor rod 41 slidable in and of greater length than a passage'42 extending through the breech block parallel to the cartridge chamber, enters the deeper end and rides along the floor of a channel 43, of gradually reducing depth, in the saddle; consequently, the extractor rod is displaced longitudinally and a tongue 44 projecting from its opposite end and fitting part way round the mouth of the cartridge chamber 11, is removed from the mouth so as to extract the spent cartridge from the chamber.

Upon rotating the unit in thereverse direction, the cam groove drives the free end of the spring arm 17 away from the breech block so that, since the firing pin and the arm 18 are locked against upwards movement by the sear rod part 25, the torsion spring is re-stresscd. During this reverse rotation, the extractor rod may be driven manually to'its initial position to enable a fresh cartridge to be inserted into the chamber 11 and the rotary travel is limited by the abutment (see FIG. 3) ofa stud 45 projecting from a longitudinal edge of the shoe 12 against an anvil 46 fixed in the left hand longitudinal edge of the saddle. As the stud 45 abuts an anvil 46, the cartridge chamber is aligned with the vertical passage 19 and a spring loaded ball 47 in the saddle is projected into a recess 48 in the shoe so as to retain the unit resiliently against clockwise rotation.

In the pistol shown in FIGS. 6 8, the edge of the shoe 12a remote from the breech block 2, is in the form of a cam.14a and the cam follower consists of a rocker 50 which is carried within a cavity 16a in the saddle 13a, by a pivot pin 51 and is loaded bya torsion spring 15a tending to turn the rocker counter-clockwise (as viewed in FIGS. 6 8) about the pin so as to retain the upperend 50a of the rocker in contact with thesaid cammed edge.

Thefiring pin 20a is formed with a V-section transverse notch 20b in its face adjacent to the muzzle of the pistol, extends through a longitudinal slot 24a in and adjacent to,the breech eridof a scar rod 25a, and is loadedby a spring (not shown) which urges the pin downwardly within thevertical passage 19a in the saddle; the muzzle end 24b of the slot in the sear rod is of V-section and the spring driven travel of the firing pin is limited by any suitable means (also not shown) so that when, as shown in FIGS. 6 and 7, the pin is at thiesaid limit, the notch is located partially below the sear rod and the upper end of the upper inclined wall of the notch is opposed to the apex of the slot end 24b.

The scar rod is loaded by a coiled compression spring 28a which tends todrivethe rod breechwards in the longitudinal passage 23a in the pistol body and, at its muzzle end, the rod is formed with an upwardly opening jaw 25b which is adapted to be engaged by a 'sear 52 on a trigger 53 pivoted in the pistol bodyAa about a transverse pin 54. h When, as shown in FIG. 8, the pistol is in its normal,

at rest condition withtherotatable barrel and breech unit at thelimit of its counter-clockwise travel and the sear rod at the limit of its spring-driven stroke in which, the slot, end 24b is engaged with the pin notch 20b, the

firing mechanism may be cocked by turning the unit clockwise whereupon the cammed shoe edge 14a turns the rocker clockwise against the action of the torsion spring 150. As the rocker turns, its lower end abuts the breech end of the sear rodand then drives the rod muzzleward against the action of the spring 28a until, when the unit reaches the end of its clockwise fmovement (see FIG. 6), the jaw 25b is engaged by the sear 52, the recess 39a is engaged by the safety catch,'the slot end 24b is spaced from the firing pin and the latter'is at the limit of its spring-driven downwards travel.

Hence, upon rotating the unit clockwise andreturning it to its initial position, the rocker is turned counterclockwise by its loading spring 15a, the lower end of the rocker-is removed from the breech end of the sear rod and the latter is held (see FIG. 7) against springdriven longitudinal catch.

During the counterclockwise return movement of the unit I, 2, a fresh cartridge may be insertedinto the cartridge chamber 11 so that, after the unit has been returned to its initial position, thumb-actuateddepres- I sion of the safety catch followed by the application of I movement by the trigger and safety body 4 or 40, and the safety catch is removed from the slot 33 by disengaging its outwardly and downwardly inclined jaw from the corresponding one of the two pins 35. The catch is then reinserted into the slot from the right hand side of the body, the said jaw is re-engaged with the other pin 35 and the grip is replaced on the underside of the body and re-secured in position by the bolt 38. Hence, when the operator is holding the grip in his left hand, he is able to actuate the safety catch with the thumb and the finger piece 27 or trigger 53 with the forefinger, of the hand.

I claim:

1. In a captive bolt pistol of the type used in humane slaughtering of animals comprising a body, a barrel housed within said body and having a muzzle and a longitudinal axis, a bolt accommodated within said barrel, a breech block for receiving a cartridge, and a firing mechanism for firing the cartridge to cause said bolt to be projected-outwardly of said muzzle into violent inpact with a skull of an animal, the improvement wherein said barrel and said breech block are incorporated into a unit which is rotatable about said longitudinal axis of said barrel between a first firing position and a second spent cartridge extraction position, and a cam is provided in said unit to cock said firing mechanism as said unit is turned from said first position 3. The improvement as claimed in claim 1, including I an open-ended housing integral with said body within which said unit is rotatable, wherein said cam is provided on an end of said breech block remote from said barrel.

4. The improvement as claimed in claim 1 wherein two projections provided in said unit extend radially of said unit and are adapted to abut said body alternately to define means for limiting rotary travel of said unit and for locating said unit in each first and second positions.

5. The improvement as claimed in claim 1, wherein said breech block is provided with a cartridge chamber having a mouth, a firing pin having a shoulder is reciprocable in said body towards and away from said mouth, and an axially displacable spring-loaded sear rod is movable in said body with respect to said firing pin, and wherein said cam consists of a groove which is formed in and circumferentially of said breech block, and a torsion spring carried in said body has opposite ends engaging respectively in said cam groove and with said firing pin whereby as said unit is turned from said first position and said second position, said torsion said body, first engagement between said first end of sa|d rocker and said cam, a trigger sear, means in said breech block defining a cartridge chamber having a mouth, a spring-loaded firing pin reciprocable in said body towards and away from said mouth, a springloaded sear rod for driving said spring-loaded firing pin towards said mouth when said unit is returned to said first position and said sear is disengaged from said rod, a second engagement between said second end of said rocker and said spring-loaded sear rod, the arrangement being such that as said rotatable unit is turned to said second position, said rocker turns against its spring loading and said second end of said rocker moves said spring-loaded sear-rod axially into engagement with said trigger sear and out of engagement with said firing pin.

7. The improvement as claimed in claim 5 wherein said sear rod is provided with a recess, and a springloaded safety catch pivoted within said body is adapted to be spring driven into engagement with said recess when said firing mechanism is cocked, a thumb-piece provided on said catch projecting beyond one side of said body to enable said catch to be depressed and disengaged from said recess.

8. The improvement as claimed in claim 6 wherein said sear rod is provided with a recess, and a springloaded safety catch pivoted within said body is adapted to be spring driven into engagement with said recess when said firing mechanism is cocked, a thumbpiece provided on said catch projecting beyond one side of said body to enable said catch to be depressed and disengaged from said recess.

9. The improvement as claimed in claim 7, wherein two pins are fixed within said body, are parallel to said sear rod, and are spaced apart transversely of said body, and a jaw at the end of said safety catch remote from said thumb piece is adapted to engage one of said pins, said catch extending beyond the other of said pins and, under spring action, tends to turn about said one pin into abutment with said other pin.

10. The improvement as claimed in claim 8, wherein two pins are fixed within said body, are parallel to said sear rod, and are spaced apart transversely of said body, and a-jaw at the end of said safety catch remote from said thumb piece is adapted to engage one of said pins, said catch extending beyond the other of said pins and, under spring action, tends to turn about said one pin into abutment with said other pin. 

1. In a captive bolt pistol of the type used in humane slaughtering of animals comprising a body, a barrel housed within said body and having a muzzle and a longitudinal axis, a bolt accommodated within said barrel, a breech block for receiving a cartridge, and a firing mechanism for firing the cartridge to cause said bolt to be projected outwardly of said muzzle into violent inpact with a skull of an animal, the improvement wherein said barrel and said breech block are incorporated into a unit which is rotatable about said longitudinal axis of said barrel between a first firing position and a second spent cartridge extraction position, and a cam is provided in said unit to cock said firing mechanism as said unit is turned from said first position to said second position.
 2. The improvement as claimed in claim 1, including a follower engaging said cam, and a pivotal connection between said follower and said body, wherein said follower is adapted to be rocked by said cam to cock said firing mechanism as said unit is turned from said first position to said second position.
 3. The improvement as claimed in claim 1, including an open-ended housing integral with said body within which said unit is rotatable, wherein said cam is provided on an end of said breech block remote from said barrel.
 4. The improvement as claimed in claim 1 wherein two projections provided in said unit extend radially of said unit and are adapted to abut said body alternately to define means for limiting rotary travel of said unit and for locating said unit in each first and second positions.
 5. The improvement as claimed in claim 1, wherein said breech block is provided with a cartridge chamber having a mouth, a firing pin having a shoulder is reciprocable in said body towards and away from said mouth, and an axially displacable spring-loaded sear rod is movable in said body with respect to said firing pin, and wherein said cam consists of a groove which is formed in and circumferentially of said breech block, and a torsion spring carried in said body has opposite ends engaging respectively in said cam groove and with said firing pin whereby as said unit is turned from said first position and said second position, said torsion spring drives said firing pin away from said mouth, and said spring-loaded sear rod is displaced axially into engagement with said shoulder to lock said firing pin against return movement as said unit is returned to said second position and said torsion spring is stressed.
 6. The improvement as claimed in claim 1, including a spring loaded rocker having first and second opposite ends, a pivotal connection between said rocker and said body, first engagement between said first end of said rocker and said cam, a trigger sear, means in said breech block defining a cartridge chamber having a mouth, a spring-loaded firing pin reciprocable in said body towards and away from said mouth, a spring-loaded sear rod for driving said spring-loaded firing pin towards said mouth when said unit is returned to said first position and said sear is disengaged from said rod, a second engagement between said second end of said rocker and said spring-loaded sear rod, the arrangement being such that as said rotatable unit is turned to said second position, said rocker turns against its spring loading and said second end of said rocker moves said spring-loaded sear-rod axially into engagement with said trigger sear and out of engagement with said firing pin.
 7. The improvement as claimed in claim 5 wherein said sear rod is provided with a recess, and a spring-loaded safety catch pivoted within said body is adapted to be spring driven into engagement with said recess when said firing mechanism is cocked, a thumb-piece provided on said catch projecting beyond one side of said body to enable said catch to be depressed and disengaged from said recess.
 8. The improvement as claimed in claim 6 wherein said sear rod is provided with a recess, and a spring-loaded safety catch pivoted within said body is adapted to be spring driven into engagement with said recess when said firing mechanism is cocked, a thumb-piece provided on said catch projecting beyond one side of said body to enable said catch to be depressed and disengaged from said recess.
 9. The improvement as claimed in claim 7, wherein two pins are fixed within said body, are parallel to said sear rod, and are spaced apart transversely of said body, and a jaw at the end of said safety catch remote from said thumb piece is adapted to engage one of said pins, said catch extending beyond the other of said pins and, under spring action, tends to turn about said one pin into abutment with said other pin.
 10. The improvement as claimed in claim 8, wherein two pins are fixed within said body, are parAllel to said sear rod, and are spaced apart transversely of said body, and a jaw at the end of said safety catch remote from said thumb piece is adapted to engage one of said pins, said catch extending beyond the other of said pins and, under spring action, tends to turn about said one pin into abutment with said other pin. 